SEEDING WITH OMENTAL CELLS PREVENTS LATE NEOINTIMAL HYPERPLASIA IN SMALL-DIAMETER DACRON GRAFTS

Background The influence of complete endothelialization of a prostheti c graft on development of late neointimal hyperplasia is unknown. This study was designed to investigate the effect of complete coverage wit h endothelial-like cells on late neointimal hyperplasia in small-diame ter Dacron grafts seeded with omental cells in a canine model. Methods and Results Four-mm-ID Dacron grafts were seeded with cells from omen tum and implanted in the carotid arteries in 24 mongrel dogs. Each dog received one seeded and one nonseeded graft. The graft patencies were assessed by angiography at 1, 5, 12, 26, and 52 weeks after surgery. The prostheses were explanted at 5, 12, 26, and 52 weeks after surgery and underwent microscopic studies. The actuarial patency rates at 1, 5, 12, 26, and 52 weeks were 100%, 95%, 95%, 95%, and 95% for seeded g rafts and 100%, 86%, 49%, 40%, and 13% for nonseeded grafts, respectiv ely. The seeded grafts exhibited a uniform endothelial-like luminal mo nolayer without the development of late neointimal proliferation or an astomotic neointimal hyperplasia. Neointimal tissue thickness increase d up to 6 months; no additional progression of the subendothelial tiss ue thickness was observed, in fact there was an insignificant decrease . Conclusions Seeding with omental cells prevents development of late neointimal hyperplasia of small diameter prosthetic vascular grafts in a canine model.